Around the world, millions of people work shifts in everything from manufacturing and the military to long-distance transport and emergency surgery. Shift workers help to keep everyday life running smoothly for the rest of us, but working nights, rotations or on-call can quickly take a toll on health and happiness.
What is shift work sleep disorder?
The ICD-10 – the World Health Organisation’s classification of medical conditions1[L1] - describes shift work sleep disorder as “A subtype of circadian rhythm sleep disorder in which the individual exhibits a normal endogenous pattern of sleep and wakefulness, but this pattern comes into conflict with the desired pattern of sleep and wakefulness required by shift work[L2] 2.” In other words, shift work obliges you to act against your body’s natural inclinations and that creates problems.
Circadian rhythms – the ‘body clock’ – regulate a wide range of physical functions including body temperature, appetite, alertness and sleepiness. Each cycle lasts approximately 24 hours and they have been fine-tuned over millions of years of evolution around a simple rule: be alert and active during daylight hours and sleep during the night. Not great news if you’re a shift worker who has to do things the other way around.
Our body clock gradually adapts to new patterns, but this can take several days. Jet-lag is a great example – it takes a few days of being awake at odd times but eventually you transition to the new time zone. People who work a regular night shift eventually make that transition, but they can still find it hard to grab enough sleep during the daytime. There’s more chance of noise or disruption, and there’s also the challenge of fitting in family and social obligations around the standard ‘daytime’ culture. As a result, they typically sleep for two to four hours less than day-shift workers[L3] 3. People who work rotating shifts have it even harder. Just as their body adapts to one set of hours, their shift pattern changes and they have to start over again.
What are the consequences?
Unfortunately, shift work tends to be bad news for our physical and emotional health. Whether it’s caused by shifts or sleep apnoea[L4] 4, being tired and under-slept can have a negative effect on attention, concentration, memory and mood. It also increases the risk of accidents on the road and in the workplace.
There can be long-term effects too. For example, studies have shown that regular shift workers have much higher rates of cardiovascular and gastrointestinal diseases than the general population[L5] 5.
What can you do to minimise the impact?
Your employer may already have adopted some tactics to minimise the negative impact of shift-working6[L6] . For example, they might have introduced shift rotations that change in a clockwise direction (a morning shift followed by a day shift followed by an evening shift, and so on). It’s usually easier for people’s bodies to adapt to this set-up than to anti-clockwise schedules.
There are also a number of things you can do to help yourself. A nap[L7] 7 before you start a night shift or during your ‘lunch’ hour can give your body a boost and help you to be more alert. Avoid alcohol before bedtime[L8] 8 (whenever that is) and make sure you eat a balanced diet with regular meal times to avoid stomach problems. Adopt – and stick to – a sleep schedule that works for you. If you’re not sure where to start, check out these tips from experienced shift workers9[L9] and this useful advice from the UK Sleep Council10 [L10] and the American Academy of Sleep Medicine[L11] 11.
Finally, good sleep starts with good sleep hygiene[L12] 12. Everyone, whether they’re a shift worker or a 9-to-5-er, should prioritise having a comfortable bed in a cool, dark room and avoiding screen time[L13] 13, caffeine14[L14] and alcohol15 [L15] before turning in.